This proposal aims to use functional magnetic resonance imaging (fMRI) to uncover the functional anatomical organization of the human brain regions involved ina the comprehension of words and sentences and to learn how these areas reorganize following focal brain injury. Language plays a unique and important role in the neurobiology of cognition. Not only is language a uniquely human enterprise, but many other cognitive behaviors rely on it. These facts become particularly evident after damage from neurological disease, when the loss of the primary means of communication is often accompanied by additional impairments in related functions. Historical approaches to the study of language processing have focused on psychometric studies of normal and impaired language users and neuroanatomical studies of patients with impaired language function caused by focal brain lesions. Functional magnetic resonance imaging (fMRI), now offers the opportunity to build on this previous work by integrating psychological and neurobiological methods into a unified study of structure/function relationships in the behavioral neurobiology of language. The high spatial resolution of fMRI, which visualizes focal brain activity by physiological changes produced during oxygen utilization, permits improved correlation of structure and function in the brain. The proposal addresses three main experimental questions; (1) What is the functional neuroanatomy of normal lexical processing, and particularly, what is the architecture of the phonological and semantic systems used by the brain to process individual swords? (2) How does the human brain process sentences in contrast to simple sequential lists of words, and what are the particular roles of syntax and temporal rate in this system? (3) What is the natural course of aphasia recovery, and how can the functional neuroanatomical basis of normal work and sentience processing improve the study of neurological impairments in language processing. Longitudinal fMRI studies of patients with aphasia from strokes will provide information on the anatomical substrate of recovery. The answers to these questions could have implications for both the basic understanding or brain function and the diagnosis and treatment of neurological diseases, including stroke, head injury, and dementia, in which language impairments contribute to serious morbidity.